The present disclosure relates generally to toners and toner processes, and more specifically, to processes for producing toners that can be fused at reduced temperatures, thereby permitting significant energy savings.
Numerous processes are within the purview of those skilled in the art for the preparation of toners, such as, for example, conventional processes wherein a resin is melt kneaded or extruded with a pigment, micronized, and pulverized to provide toner particles. Toner can also be produced by emulsion aggregation methods. Methods of preparing an emulsion aggregation (EA) type toner are within the purview of those skilled in the art, and toners may be formed by aggregating a colorant with a latex polymer formed by emulsion polymerization. For example, U.S. Pat. No. 5,853,943, the disclosure of which is hereby incorporated by reference in its entirety, is directed to a semi-continuous emulsion polymerization process for preparing a latex by first forming a seed polymer. Other examples of emulsion/aggregation/coalescing processes for the preparation of toners include those illustrated in U.S. Pat. Nos. 5,403,693, 5,418,108, 5,364,729, and 5,346,797, the disclosures of each of which are hereby incorporated by reference in their entirety. Other processes are disclosed in U.S. Pat. Nos. 5,527,658, 5,585,215, 5,650,255, 5,650,256 and 5,501,935, the disclosures of each of which are hereby incorporated by reference in their entirety.
Methods for reducing the energy required for fusing or melting toners to a substrate, and thus reducing energy costs, are desirable. To date, within the electrophotographic printing area, one strategy has been the development of ultra-low melt (ULM) polyester-based EA toners that are based on a mixture of a crystalline polymer and a glassy amorphous polymer. These toners can be fused at lower temperatures than conventional toners, resulting in significant energy savings. Additional benefits of ultra-low melt toner technology include the potential for faster print speeds, faster start-up times, and reduced fuser wear.
Despite these advances, energy consumption in electrophotographic printing is still dominated by the fusing subsystem, which is responsible for a significant portion of the power required by an electrophotographic printer.
Hence, toner compositions produced with decreased energy requirements during printing that perform similar to conventional toners remain desirable.